Particle velocity and stress measurements in low density HMX

Magnetic particle velocity gauges and PVDF stress rate gauges have been used to measure the shock response of low density HMX explosive (1.24) g/cm3. In experiments done at LANL, magnetic particle velocity gauges were located on both sides of the explosive. In nearly identical experiments done at SNL, PVDF stress rate gauges were located at the same positions. Using these techniques both particle velocity and stess histories were obtained for a particular experimental condition. Loading and reaction paths were established in the stress‐particle velocity plane for each input condition. This information was used to determine that compacted HMX has an impedance close to that of Kel‐F and also that a global reaction rate of ≊0.13 μs−1 was observed in HMX shocked to about 0.8 GPa. At low input stresses the transmitted wave profiles had long rise times (up to 1 μs) due to the compaction processes.